The invention relates to a charge system comprising a vehicle with a charge socket and with a contactor switching unit, and comprising a charger device for charging an electrical energy accumulator of the vehicle from a vehicle-external AC power system.
Plug-in hybrid and electric vehicles have at least one charging interface which permits an electrical energy accumulator of the vehicle to be charged from an external electrical energy source.
In the prior art, charge systems are known in which a charger device makes available electrical DC voltage in order to charge a traction battery. This is described, for example, in US 2004/0130288 A1. The charger device is a component of a charging architecture of the vehicle. According to the same document, what is referred to as electric vehicle service equipment (EVSE) according to the specification SAE J1772 is located outside the vehicle, said specification dealing with electrical and electronic specifications for the charge transfer from the external power source to the vehicle.
An object of the invention is to provide an improved charge system comprising a vehicle with a charge socket and a contactor switching unit and comprising a charger device for charging an electrical energy accumulator of the vehicle from a vehicle-external AC power system.
This and other objects are achieved according to the invention, wherein the charger device is a vehicle-external and portable charger device which comprises a DC-DC converter, a first charging cable with an AC power system plug and a second charging cable with a charge plug.
This means that the vehicle can be charged with DC current from an external AC power source. The charger device rectifies the power which originates from the source and is transferred by the first charging cable. The vehicle is supplied by the charger device with a DC voltage via the second charging cable. The charger device, together with the cabling, is portable. The charging cables can be permanently connected to the charger device. That is to say, the charging of the vehicle can be charged independently of locations of DC charging stations at any desired access to the AC power system. However, since the charger device is not permanently integrated into the vehicle, valuable installation space can be provided for another use or for a more compact design of the vehicle with a lower overall mass. In particular, for short-distance journeys or on routes with an available DC charging infrastructure (for example, DC recharging stations, charging stations) the need to carry along a mobile charger device can be entirely eliminated.
According to a further embodiment of the invention, the charger device comprises a housing which has external cooling fins and through which at least one cooling duct runs. This cooling duct is configured for a flow of air through the housing.
The cooling fins and the at least one cooling duct bring about air cooling of the charger device. Since the latter is located outside the vehicle, the convective circulation of the ambient air permits the heat, which is produced during the rectification to be transported away. The cooling fins and the cooling duct improve the heat transfer by enlarging the surface which is in contact with the surroundings. Given a preferred vertical orientation, a directed flow is produced, i.e. a flow with a preferred flow direction counter to gravity, which is also referred to as a “chimney effect” and which, additionally, promotes the heat transfer.
Furthermore, it is advantageous if the housing has a first lid and a second lid. The housing, the first lid and the second lid form a winding reel. And, the first charging cable and the second charging cable can each be wound on to the winding reel.
By virtue of the design of the charger device, the cables which are associated with the charger device can be wound on to the charger device.
Alternatively, the housing can have an automatic cable retractor, for the first charging cable and for the second charging cable, respectively.
Automatic cable retractors may be configured, for example, as a cable rolling drive with a main spring.
According to a further embodiment of the invention, the charger device has at least one thermally insulated carrying handle and at least one thermally insulated stand.
Power electronics of the DC-DC converter of the charger device generate heat during rectification. A carrying handle which does not conduct heat, or only conducts heat poorly, ensures a thermal contact protection for the user during a charging process. A stand which does not conduct heat or only conducts heat poorly prevents heat from being transferred to a standing surface of the charger device.
As a result of the at least one stand, the charger device can be positioned on a standing surface for charging. On this standing surface, for example a garage floor, the stand supports the charger device in a non-tilting fashion.
It is also advantageous if the charger device comprises at least one foldable carrying handle and at least one foldable stand, and the at least one carrying handle secures, in a folded-in state, a charging cable which is wound on to the winding reel, and the at least one stand secures, in a folded-in state, a charging cable which is wound on to the winding reel.
It can therefore be ensured that the winding of a wound-on cable permanently has stability when the carrying handle is folded in and when the stand is folded in, and the cable winding does not slip down from the winding reel.
According to a further variant, the vehicle comprises a storage space and the storage space is configured to transport the portable charger device.
In the storage space, the charger device can be carried along by a user in the vehicle. In this way, the vehicle can be charged independently of the location at any place where there is access to an AC power system. This is particularly advantageous for relatively long routes with uncertainty about the availability of DC charging sources along the route.
Furthermore, the vehicle comprises a charge control unit which unidirectionally detects charge control signals from the charger device via the second charging cable. The signals are preferably control signals which are necessary for controlling the charging sequence of a DC charging method.
The charger device can also have a charging communication unit. Data communication between the charger device and the vehicle can be established between the charge communication unit and the charge control unit via the second charging cable when the charge plug is plugged into the charge socket. This charge communication permits the charging process to be regulated and monitored with the charger device.
The charger device can additionally have a protection circuit between the two charger cables, which protection circuit satisfies the safety requirements of an EVSE according to SAE J1772. This also comprises a logic for setting a maximum charge current and a voltage disconnection unit.
According to one preferred embodiment of the invention, the system comprises an attachment mechanism for a wall to which the charger device can be secured by means of the at least one carrying handle for the purpose of charging or storage. This means that the charger device can be attached to a wall using the carrying handle and the attachment mechanism. According to this embodiment, the charger device can be configured alternatively for attachment to a wall or for positioning on a standing surface.
According to a further embodiment of the invention, the at least one carrying handle comprises a holding rail with which the charger device can be hung from a partially lowered side window of the vehicle. By closing the window and locking the vehicle, which can be triggered, for example, via the user by means of a remote control key of the vehicle or by means of data communication between the charger device and the charge control unit when a connection is established between the charge plug and the charge socket, the charger device can be clamped by the carrying handle between the window and the associated window frame and, therefore, protected against theft.
The invention is based on the ideas presented below.
The prior art describes cable-bound charging for charging electric vehicles and plug-in hybrid vehicles, both as AC charging and as DC charging. In the case of AC charging, the charger device is accommodated in the vehicle. In the case of DC charging, the conversion of the AC current takes place in a charging station, a wall box or a charging pillar outside the vehicle. Standards for interfaces for the vehicle are currently under development for both methods. A charging infrastructure for AC charging requires a considerable integration expenditure in the vehicle as a function of the power requirement. DC charging permits significantly higher charging powers than AC charging.
In order to permit DC charging independently of DC charging stations or wall boxes, for example at sockets which are customary in the domestic sphere, an AC/DC charger device is to be additionally integrated into the vehicle. This means that a charger device which is installed in the vehicle, which takes up installation space in the vehicle and which constitutes additional vehicle weight is to be carried along. In addition, a suitable charging cable is to be carried along which is equipped partly with prescribed safety functions in order to produce a connection between the vehicle-external AC power source and the AC/DC charger device in the vehicle.
Therefore, in one preferred embodiment, a mobile charger device with two charging cables which converts AC current into DC current outside the vehicle and comprises prescribed safety functions is proposed. A mobile charger device provides a reduction in weight in the vehicle and can be replaced with other mobile charger devices with a different electrical power. What limits the power is the maximum power level which can be drawn from the AC power system to which power level the current-carrying capacity of the charging cable which connects the AC power source to the charger device can be adapted.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.